The Radium Girls: How an entire workforce was killed by radiation poisoning

Author Kate Moore tells the tragic tale of the dial-painters poisoned by radium…

The radium girls were the American dial-painters from the 1920s who were poisoned by their work. They painted numbers on watches, clocks and aeronautical dials with luminous radium paint to make them glow in the dark, and were instructed to lip-point – to put the brushes in their mouths to make a fine point. With each dial they painted, the women took into their bodies a minute amount of radium. A few years later, they sickened and died from a type of radiation poisoning never before seen in humans. This is what the pioneering doctors of the time discovered had happened inside them.

A dial-painter with a radium-induced sarcoma of the chin
A dial-painter with a radium-induced sarcoma of the chin


Radium is chemically similar to calcium, which is a bone-seeker. When we drink a glass of milk, the calcium in it deposits in our bones to make them strong. Radium acts identically – except it destroys the bone. When the dial-painters swallowed it, the radium entered their bones and once there became impossible to remove, with a half-life of 1,600 years. By the time they became sick, the women were already doomed to die.

Powerful radiation

Radium is highly radioactive. Almost from the moment it was discovered by the Curies in 1898, scientists realised it was dangerous, as many suffered radiation burns from handling it. Pierre Curie remarked that a kilo of radium ‘would burn all the skin off his body, destroy his eyesight and probably kill him’. Workers handling large amounts learned to protect themselves with lead aprons, which blocked the alpha, beta and gamma rays radium emitted.

The alpha rays, according to Dr Harrison Martland, are ‘physiologically and biologically intensely more irritating than beta or gamma’ rays. Fortunately, although they are powerful, they are unable to penetrate the skin, so this particularly hazardous radiation did not affect most workers.

But in the radium girls, the alpha rays were now inside them. ‘Radium, once deposited in bone,’ wrote Dr Cecil K. Drinker of Harvard University, ‘would be in a position to produce peculiarly effective damage, many thousand times greater than the same amount outside.’

Honey-combed bones

The first symptom of radium poisoning for most dial-painters was tooth trouble; perhaps to be expected given the lip-pointing technique. Their teeth fell out – they were ‘flinty’ and ‘moth-eaten’ – and then their jawbones eroded; one woman’s was said to be reduced ‘to a mere stump’. This was called jaw necrosis (necrosis means death of tissue).

The radium also settled in other bones throughout their bodies, while the women’s organs were discovered to be radioactive too. Dial-painters found their legs shortened by as much as 4 inches, or that their spines were crushed, forcing them to wear steel back braces to keep them upright. Their hips locked into place so they couldn’t walk and they suffered spontaneous fractures. The radium literally ate their bones away, riddling holes all the way through. This process happened while they were still alive and earned the dial-painters the nickname of ‘the Living Dead’.

A dial-painter with a radium-induced cancer of the knee.
A dial-painter with a radium-induced cancer of the knee.

Changes in the blood

With the radium deposited in the bones, next to the bone marrow where the blood-producing centres lie, the dial-painters also suffered severe and fatal anaemia. At first, ironically, the radium’s stimulation of the bone marrow was thought to be a positive thing – something that was exploited by commercial radium companies – but it soon became overstimulation. Dr Frederick Hoffman said, ‘The cumulative effect was disastrous, destroying the red blood cells.’

A sting in the tail

Radium poisoning was proven to exist in 1925. By that time, many dial-painters had died of anaemia or jaw necrosis, but there were others still living who had not yet succumbed to their poisoning. Doctors were hopeful this meant they would ultimately live, despite being crippled.

But in December 1927 the first dial-painter case of a sarcoma – a bone tumour – was identified. These sarcomas were huge tumours that could sprout anywhere on the women: on their spines, hips, eyes, elbows, knees… Martland said of one woman with a pelvic tumour: ‘You couldn’t take the whole mass out without taking the woman apart. The whole mass was larger than two footballs.’ These sarcomas became ticking time bombs in the dial-painters; many only started growing decades after the women had painted dials. Depending on the location of the sarcoma, some dial-painters had the option of amputating limbs to save their lives – but for others there was no hope. So, for years afterwards, the headlines still ran: RADIUM, DORMANT KILLER, AT WORK AGAIN.

The Radium Girls by Kate Moore, published by Simon & Schuster, is available now.

The Radium Girls by Kate Moore
The Radium Girls by Kate Moore